mm/bootmem.c

   1 /*
   2  *  bootmem - A boot-time physical memory allocator and configurator
   3  *
   4  *  Copyright (C) 1999 Ingo Molnar
   5  *                1999 Kanoj Sarcar, SGI
   6  *                2008 Johannes Weiner
   7  *
   8  * Access to this subsystem has to be serialized externally (which is true
   9  * for the boot process anyway).
  10  */
  11 #include <linux/init.h>
  12 #include <linux/pfn.h>
  13 #include <linux/slab.h>
  14 #include <linux/bootmem.h>
  15 #include <linux/module.h>
  16 #include <linux/kmemleak.h>
  17 #include <linux/range.h>
  18 #include <linux/memblock.h>
  19
  20 #include <asm/bug.h>
  21 #include <asm/io.h>
  22 #include <asm/processor.h>
  23
  24 #include "internal.h"
  25
  26 #ifndef CONFIG_NEED_MULTIPLE_NODES
  27 struct pglist_data __refdata contig_page_data = {
  28         .bdata = &bootmem_node_data[0]
  29 };
  30 EXPORT_SYMBOL(contig_page_data);
  31 #endif
  32
  33 unsigned long max_low_pfn;
  34 unsigned long min_low_pfn;
  35 unsigned long max_pfn;
  36
  37 #ifdef CONFIG_CRASH_DUMP
  38 /*
  39  * If we have booted due to a crash, max_pfn will be a very low value. We need
  40  * to know the amount of memory that the previous kernel used.
  41  */
  42 unsigned long saved_max_pfn;
  43 #endif
  44
  45 bootmem_data_t bootmem_node_data[MAX_NUMNODES] __initdata;
  46
  47 static struct list_head bdata_list __initdata = LIST_HEAD_INIT(bdata_list);
  48
  49 static int bootmem_debug;
  50
  51 static int __init bootmem_debug_setup(char *buf)
  52 {
  53         bootmem_debug = 1;
  54         return 0;
  55 }
  56 early_param("bootmem_debug", bootmem_debug_setup);
  57
  58 #define bdebug(fmt, args...) ({                         \
  59         if (unlikely(bootmem_debug))                    \
  60                 printk(KERN_INFO                        \
  61                         "bootmem::%s " fmt,             \
  62                         __func__, ## args);             \
  63 })
  64
  65 static unsigned long __init bootmap_bytes(unsigned long pages)
  66 {
  67         unsigned long bytes = (pages + 7) / 8;
  68
  69         return ALIGN(bytes, sizeof(long));
  70 }
  71
  72 /**
  73  * bootmem_bootmap_pages - calculate bitmap size in pages
  74  * @pages: number of pages the bitmap has to represent
  75  */
  76 unsigned long __init bootmem_bootmap_pages(unsigned long pages)
  77 {
  78         unsigned long bytes = bootmap_bytes(pages);
  79
  80         return PAGE_ALIGN(bytes) >> PAGE_SHIFT;
  81 }
  82
  83 /*
  84  * link bdata in order
  85  */
  86 static void __init link_bootmem(bootmem_data_t *bdata)
  87 {
  88         struct list_head *iter;
  89
  90         list_for_each(iter, &bdata_list) {
  91                 bootmem_data_t *ent;
  92
  93                 ent = list_entry(iter, bootmem_data_t, list);
  94                 if (bdata->node_min_pfn < ent->node_min_pfn)
  95                         break;
  96         }
  97         list_add_tail(&bdata->list, iter);
  98 }
  99
 100 /*
 101  * Called once to set up the allocator itself.
 102  */
 103 static unsigned long __init init_bootmem_core(bootmem_data_t *bdata,
 104         unsigned long mapstart, unsigned long start, unsigned long end)
 105 {
 106         unsigned long mapsize;
 107
 108         mminit_validate_memmodel_limits(&start, &end);
 109         bdata->node_bootmem_map = phys_to_virt(PFN_PHYS(mapstart));
 110         bdata->node_min_pfn = start;
 111         bdata->node_low_pfn = end;
 112         link_bootmem(bdata);
 113
 114         /*
 115          * Initially all pages are reserved - setup_arch() has to
 116          * register free RAM areas explicitly.
 117          */
 118         mapsize = bootmap_bytes(end - start);
 119         memset(bdata->node_bootmem_map, 0xff, mapsize);
 120
 121         bdebug("nid=%td start=%lx map=%lx end=%lx mapsize=%lx\n",
 122                 bdata - bootmem_node_data, start, mapstart, end, mapsize);
 123
 124         return mapsize;
 125 }
 126
 127 /**
 128  * init_bootmem_node - register a node as boot memory
 129  * @pgdat: node to register
 130  * @freepfn: pfn where the bitmap for this node is to be placed
 131  * @startpfn: first pfn on the node
 132  * @endpfn: first pfn after the node
 133  *
 134  * Returns the number of bytes needed to hold the bitmap for this node.
 135  */
 136 unsigned long __init init_bootmem_node(pg_data_t *pgdat, unsigned long freepfn,
 137                                 unsigned long startpfn, unsigned long endpfn)
 138 {
 139         return init_bootmem_core(pgdat->bdata, freepfn, startpfn, endpfn);
 140 }
 141
 142 /**
 143  * init_bootmem - register boot memory
 144  * @start: pfn where the bitmap is to be placed
 145  * @pages: number of available physical pages
 146  *
 147  * Returns the number of bytes needed to hold the bitmap.
 148  */
 149 unsigned long __init init_bootmem(unsigned long start, unsigned long pages)
 150 {
 151         max_low_pfn = pages;
 152         min_low_pfn = start;
 153         return init_bootmem_core(NODE_DATA(0)->bdata, start, 0, pages);
 154 }
 155
 156 /*
 157  * free_bootmem_late - free bootmem pages directly to page allocator
 158  * @addr: starting address of the range
 159  * @size: size of the range in bytes
 160  *
 161  * This is only useful when the bootmem allocator has already been torn
 162  * down, but we are still initializing the system.  Pages are given directly
 163  * to the page allocator, no bootmem metadata is updated because it is gone.
 164  */
 165 void __init free_bootmem_late(unsigned long addr, unsigned long size)
 166 {
 167         unsigned long cursor, end;
 168
 169         kmemleak_free_part(__va(addr), size);
 170
 171         cursor = PFN_UP(addr);
 172         end = PFN_DOWN(addr + size);
 173
 174         for (; cursor < end; cursor++) {
 175                 __free_pages_bootmem(pfn_to_page(cursor), 0);
 176                 totalram_pages++;
 177         }
 178 }
 179
 180 static unsigned long __init free_all_bootmem_core(bootmem_data_t *bdata)
 181 {
 182         int aligned;
 183         struct page *page;
 184         unsigned long start, end, pages, count = 0;
 185
 186         if (!bdata->node_bootmem_map)
 187                 return 0;
 188
 189         start = bdata->node_min_pfn;
 190         end = bdata->node_low_pfn;
 191
 192         /*
 193          * If the start is aligned to the machines wordsize, we might
 194          * be able to free pages in bulks of that order.
 195          */
 196         aligned = !(start & (BITS_PER_LONG - 1));
 197
 198         bdebug("nid=%td start=%lx end=%lx aligned=%d\n",
 199                 bdata - bootmem_node_data, start, end, aligned);
 200
 201         while (start < end) {
 202                 unsigned long *map, idx, vec;
 203
 204                 map = bdata->node_bootmem_map;
 205                 idx = start - bdata->node_min_pfn;
 206                 vec = ~map[idx / BITS_PER_LONG];
 207
 208                 if (aligned && vec == ~0UL && start + BITS_PER_LONG < end) {
 209                         int order = ilog2(BITS_PER_LONG);
 210
 211                         __free_pages_bootmem(pfn_to_page(start), order);
 212                         count += BITS_PER_LONG;
 213                 } else {
 214                         unsigned long off = 0;
 215
 216                         while (vec && off < BITS_PER_LONG) {
 217                                 if (vec & 1) {
 218                                         page = pfn_to_page(start + off);
 219                                         __free_pages_bootmem(page, 0);
 220                                         count++;
 221                                 }
 222                                 vec >>= 1;
 223                                 off++;
 224                         }
 225                 }
 226                 start += BITS_PER_LONG;
 227         }
 228
 229         page = virt_to_page(bdata->node_bootmem_map);
 230         pages = bdata->node_low_pfn - bdata->node_min_pfn;
 231         pages = bootmem_bootmap_pages(pages);
 232         count += pages;
 233         while (pages--)
 234                 __free_pages_bootmem(page++, 0);
 235
 236         bdebug("nid=%td released=%lx\n", bdata - bootmem_node_data, count);
 237
 238         return count;
 239 }
 240
 241 /**
 242  * free_all_bootmem_node - release a node's free pages to the buddy allocator
 243  * @pgdat: node to be released
 244  *
 245  * Returns the number of pages actually released.
 246  */
 247 unsigned long __init free_all_bootmem_node(pg_data_t *pgdat)
 248 {
 249         register_page_bootmem_info_node(pgdat);
 250         return free_all_bootmem_core(pgdat->bdata);
 251 }
 252
 253 /**
 254  * free_all_bootmem - release free pages to the buddy allocator
 255  *
 256  * Returns the number of pages actually released.
 257  */
 258 unsigned long __init free_all_bootmem(void)
 259 {
 260         unsigned long total_pages = 0;
 261         bootmem_data_t *bdata;
 262
 263         list_for_each_entry(bdata, &bdata_list, list)
 264                 total_pages += free_all_bootmem_core(bdata);
 265
 266         return total_pages;
 267 }
 268
 269 static void __init __free(bootmem_data_t *bdata,
 270                         unsigned long sidx, unsigned long eidx)
 271 {
 272         unsigned long idx;
 273
 274         bdebug("nid=%td start=%lx end=%lx\n", bdata - bootmem_node_data,
 275                 sidx + bdata->node_min_pfn,
 276                 eidx + bdata->node_min_pfn);
 277
 278         if (bdata->hint_idx > sidx)
 279                 bdata->hint_idx = sidx;
 280
 281         for (idx = sidx; idx < eidx; idx++)
 282                 if (!test_and_clear_bit(idx, bdata->node_bootmem_map))
 283                         BUG();
 284 }
 285
 286 static int __init __reserve(bootmem_data_t *bdata, unsigned long sidx,
 287                         unsigned long eidx, int flags)
 288 {
 289         unsigned long idx;
 290         int exclusive = flags & BOOTMEM_EXCLUSIVE;
 291
 292         bdebug("nid=%td start=%lx end=%lx flags=%x\n",
 293                 bdata - bootmem_node_data,
 294                 sidx + bdata->node_min_pfn,
 295                 eidx + bdata->node_min_pfn,
 296                 flags);
 297
 298         for (idx = sidx; idx < eidx; idx++)
 299                 if (test_and_set_bit(idx, bdata->node_bootmem_map)) {
 300                         if (exclusive) {
 301                                 __free(bdata, sidx, idx);
 302                                 return -EBUSY;
 303                         }
 304                         bdebug("silent double reserve of PFN %lx\n",
 305                                 idx + bdata->node_min_pfn);
 306                 }
 307         return 0;
 308 }
 309
 310 static int __init mark_bootmem_node(bootmem_data_t *bdata,
 311                                 unsigned long start, unsigned long end,
 312                                 int reserve, int flags)
 313 {
 314         unsigned long sidx, eidx;
 315
 316         bdebug("nid=%td start=%lx end=%lx reserve=%d flags=%x\n",
 317                 bdata - bootmem_node_data, start, end, reserve, flags);
 318
 319         BUG_ON(start < bdata->node_min_pfn);
 320         BUG_ON(end > bdata->node_low_pfn);
 321
 322         sidx = start - bdata->node_min_pfn;
 323         eidx = end - bdata->node_min_pfn;
 324
 325         if (reserve)
 326                 return __reserve(bdata, sidx, eidx, flags);
 327         else
 328                 __free(bdata, sidx, eidx);
 329         return 0;
 330 }
 331
 332 static int __init mark_bootmem(unsigned long start, unsigned long end,
 333                                 int reserve, int flags)
 334 {
 335         unsigned long pos;
 336         bootmem_data_t *bdata;
 337
 338         pos = start;
 339         list_for_each_entry(bdata, &bdata_list, list) {
 340                 int err;
 341                 unsigned long max;
 342
 343                 if (pos < bdata->node_min_pfn ||
 344                     pos >= bdata->node_low_pfn) {
 345                         BUG_ON(pos != start);
 346                         continue;
 347                 }
 348
 349                 max = min(bdata->node_low_pfn, end);
 350
 351                 err = mark_bootmem_node(bdata, pos, max, reserve, flags);
 352                 if (reserve && err) {
 353                         mark_bootmem(start, pos, 0, 0);
 354                         return err;
 355                 }
 356
 357                 if (max == end)
 358                         return 0;
 359                 pos = bdata->node_low_pfn;
 360         }
 361         BUG();
 362 }
 363
 364 /**
 365  * free_bootmem_node - mark a page range as usable
 366  * @pgdat: node the range resides on
 367  * @physaddr: starting address of the range
 368  * @size: size of the range in bytes
 369  *
 370  * Partial pages will be considered reserved and left as they are.
 371  *
 372  * The range must reside completely on the specified node.
 373  */
 374 void __init free_bootmem_node(pg_data_t *pgdat, unsigned long physaddr,
 375                               unsigned long size)
 376 {
 377         unsigned long start, end;
 378
 379         kmemleak_free_part(__va(physaddr), size);
 380
 381         start = PFN_UP(physaddr);
 382         end = PFN_DOWN(physaddr + size);
 383
 384         mark_bootmem_node(pgdat->bdata, start, end, 0, 0);
 385 }
 386
 387 /**
 388  * free_bootmem - mark a page range as usable
 389  * @addr: starting address of the range
 390  * @size: size of the range in bytes
 391  *
 392  * Partial pages will be considered reserved and left as they are.
 393  *
 394  * The range must be contiguous but may span node boundaries.
 395  */
 396 void __init free_bootmem(unsigned long addr, unsigned long size)
 397 {
 398         unsigned long start, end;
 399
 400         kmemleak_free_part(__va(addr), size);
 401
 402         start = PFN_UP(addr);
 403         end = PFN_DOWN(addr + size);
 404
 405         mark_bootmem(start, end, 0, 0);
 406 }
 407
 408 /**
 409  * reserve_bootmem_node - mark a page range as reserved
 410  * @pgdat: node the range resides on
 411  * @physaddr: starting address of the range
 412  * @size: size of the range in bytes
 413  * @flags: reservation flags (see linux/bootmem.h)
 414  *
 415  * Partial pages will be reserved.
 416  *
 417  * The range must reside completely on the specified node.
 418  */
 419 int __init reserve_bootmem_node(pg_data_t *pgdat, unsigned long physaddr,
 420                                  unsigned long size, int flags)
 421 {
 422         unsigned long start, end;
 423
 424         start = PFN_DOWN(physaddr);
 425         end = PFN_UP(physaddr + size);
 426
 427         return mark_bootmem_node(pgdat->bdata, start, end, 1, flags);
 428 }
 429
 430 /**
 431  * reserve_bootmem - mark a page range as usable
 432  * @addr: starting address of the range
 433  * @size: size of the range in bytes
 434  * @flags: reservation flags (see linux/bootmem.h)
 435  *
 436  * Partial pages will be reserved.
 437  *
 438  * The range must be contiguous but may span node boundaries.
 439  */
 440 int __init reserve_bootmem(unsigned long addr, unsigned long size,
 441                             int flags)
 442 {
 443         unsigned long start, end;
 444
 445         start = PFN_DOWN(addr);
 446         end = PFN_UP(addr + size);
 447
 448         return mark_bootmem(start, end, 1, flags);
 449 }
 450
 451 int __weak __init reserve_bootmem_generic(unsigned long phys, unsigned long len,
 452                                    int flags)
 453 {
 454         return reserve_bootmem(phys, len, flags);
 455 }
 456
 457 static unsigned long __init align_idx(struct bootmem_data *bdata,
 458                                       unsigned long idx, unsigned long step)
 459 {
 460         unsigned long base = bdata->node_min_pfn;
 461
 462         /*
 463          * Align the index with respect to the node start so that the
 464          * combination of both satisfies the requested alignment.
 465          */
 466
 467         return ALIGN(base + idx, step) - base;
 468 }
 469
 470 static unsigned long __init align_off(struct bootmem_data *bdata,
 471                                       unsigned long off, unsigned long align)
 472 {
 473         unsigned long base = PFN_PHYS(bdata->node_min_pfn);
 474
 475         /* Same as align_idx for byte offsets */
 476
 477         return ALIGN(base + off, align) - base;
 478 }
 479
 480 static void * __init alloc_bootmem_core(struct bootmem_data *bdata,
 481                                         unsigned long size, unsigned long align,
 482                                         unsigned long goal, unsigned long limit)
 483 {
 484         unsigned long fallback = 0;
 485         unsigned long min, max, start, sidx, midx, step;
 486
 487         bdebug("nid=%td size=%lx [%lu pages] align=%lx goal=%lx limit=%lx\n",
 488                 bdata - bootmem_node_data, size, PAGE_ALIGN(size) >> PAGE_SHIFT,
 489                 align, goal, limit);
 490
 491         BUG_ON(!size);
 492         BUG_ON(align & (align - 1));
 493         BUG_ON(limit && goal + size > limit);
 494
 495         if (!bdata->node_bootmem_map)
 496                 return NULL;
 497
 498         min = bdata->node_min_pfn;
 499         max = bdata->node_low_pfn;
 500
 501         goal >>= PAGE_SHIFT;
 502         limit >>= PAGE_SHIFT;
 503
 504         if (limit && max > limit)
 505                 max = limit;
 506         if (max <= min)
 507                 return NULL;
 508
 509         step = max(align >> PAGE_SHIFT, 1UL);
 510
 511         if (goal && min < goal && goal < max)
 512                 start = ALIGN(goal, step);
 513         else
 514                 start = ALIGN(min, step);
 515
 516         sidx = start - bdata->node_min_pfn;
 517         midx = max - bdata->node_min_pfn;
 518
 519         if (bdata->hint_idx > sidx) {
 520                 /*
 521                  * Handle the valid case of sidx being zero and still
 522                  * catch the fallback below.
 523                  */
 524                 fallback = sidx + 1;
 525                 sidx = align_idx(bdata, bdata->hint_idx, step);
 526         }
 527
 528         while (1) {
 529                 int merge;
 530                 void *region;
 531                 unsigned long eidx, i, start_off, end_off;
 532 find_block:
 533                 sidx = find_next_zero_bit(bdata->node_bootmem_map, midx, sidx);
 534                 sidx = align_idx(bdata, sidx, step);
 535                 eidx = sidx + PFN_UP(size);
 536
 537                 if (sidx >= midx || eidx > midx)
 538                         break;
 539
 540                 for (i = sidx; i < eidx; i++)
 541                         if (test_bit(i, bdata->node_bootmem_map)) {
 542                                 sidx = align_idx(bdata, i, step);
 543                                 if (sidx == i)
 544                                         sidx += step;
 545                                 goto find_block;
 546                         }
 547
 548                 if (bdata->last_end_off & (PAGE_SIZE - 1) &&
 549                                 PFN_DOWN(bdata->last_end_off) + 1 == sidx)
 550                         start_off = align_off(bdata, bdata->last_end_off, align);
 551                 else
 552                         start_off = PFN_PHYS(sidx);
 553
 554                 merge = PFN_DOWN(start_off) < sidx;
 555                 end_off = start_off + size;
 556
 557                 bdata->last_end_off = end_off;
 558                 bdata->hint_idx = PFN_UP(end_off);
 559
 560                 /*
 561                  * Reserve the area now:
 562                  */
 563                 if (__reserve(bdata, PFN_DOWN(start_off) + merge,
 564                                 PFN_UP(end_off), BOOTMEM_EXCLUSIVE))
 565                         BUG();
 566
 567                 region = phys_to_virt(PFN_PHYS(bdata->node_min_pfn) +
 568                                 start_off);
 569                 memset(region, 0, size);
 570                 /*
 571                  * The min_count is set to 0 so that bootmem allocated blocks
 572                  * are never reported as leaks.
 573                  */
 574                 kmemleak_alloc(region, size, 0, 0);
 575                 return region;
 576         }
 577
 578         if (fallback) {
 579                 sidx = align_idx(bdata, fallback - 1, step);
 580                 fallback = 0;
 581                 goto find_block;
 582         }
 583
 584         return NULL;
 585 }
 586
 587 static void * __init alloc_arch_preferred_bootmem(bootmem_data_t *bdata,
 588                                         unsigned long size, unsigned long align,
 589                                         unsigned long goal, unsigned long limit)
 590 {
 591         if (WARN_ON_ONCE(slab_is_available()))
 592                 return kzalloc(size, GFP_NOWAIT);
 593
 594 #ifdef CONFIG_HAVE_ARCH_BOOTMEM
 595         {
 596                 bootmem_data_t *p_bdata;
 597
 598                 p_bdata = bootmem_arch_preferred_node(bdata, size, align,
 599                                                         goal, limit);
 600                 if (p_bdata)
 601                         return alloc_bootmem_core(p_bdata, size, align,
 602                                                         goal, limit);
 603         }
 604 #endif
 605         return NULL;
 606 }
 607
 608 static void * __init ___alloc_bootmem_nopanic(unsigned long size,
 609                                         unsigned long align,
 610                                         unsigned long goal,
 611                                         unsigned long limit)
 612 {
 613         bootmem_data_t *bdata;
 614         void *region;
 615
 616 restart:
 617         region = alloc_arch_preferred_bootmem(NULL, size, align, goal, limit);
 618         if (region)
 619                 return region;
 620
 621         list_for_each_entry(bdata, &bdata_list, list) {
 622                 if (goal && bdata->node_low_pfn <= PFN_DOWN(goal))
 623                         continue;
 624                 if (limit && bdata->node_min_pfn >= PFN_DOWN(limit))
 625                         break;
 626
 627                 region = alloc_bootmem_core(bdata, size, align, goal, limit);
 628                 if (region)
 629                         return region;
 630         }
 631
 632         if (goal) {
 633                 goal = 0;
 634                 goto restart;
 635         }
 636
 637         return NULL;
 638 }
 639
 640 /**
 641  * __alloc_bootmem_nopanic - allocate boot memory without panicking
 642  * @size: size of the request in bytes
 643  * @align: alignment of the region
 644  * @goal: preferred starting address of the region
 645  *
 646  * The goal is dropped if it can not be satisfied and the allocation will
 647  * fall back to memory below @goal.
 648  *
 649  * Allocation may happen on any node in the system.
 650  *
 651  * Returns NULL on failure.
 652  */
 653 void * __init __alloc_bootmem_nopanic(unsigned long size, unsigned long align,
 654                                         unsigned long goal)
 655 {
 656         unsigned long limit = 0;
 657
 658         return ___alloc_bootmem_nopanic(size, align, goal, limit);
 659 }
 660
 661 static void * __init ___alloc_bootmem(unsigned long size, unsigned long align,
 662                                         unsigned long goal, unsigned long limit)
 663 {
 664         void *mem = ___alloc_bootmem_nopanic(size, align, goal, limit);
 665
 666         if (mem)
 667                 return mem;
 668         /*
 669          * Whoops, we cannot satisfy the allocation request.
 670          */
 671         printk(KERN_ALERT "bootmem alloc of %lu bytes failed!\n", size);
 672         panic("Out of memory");
 673         return NULL;
 674 }
 675
 676 /**
 677  * __alloc_bootmem - allocate boot memory
 678  * @size: size of the request in bytes
 679  * @align: alignment of the region
 680  * @goal: preferred starting address of the region
 681  *
 682  * The goal is dropped if it can not be satisfied and the allocation will
 683  * fall back to memory below @goal.
 684  *
 685  * Allocation may happen on any node in the system.
 686  *
 687  * The function panics if the request can not be satisfied.
 688  */
 689 void * __init __alloc_bootmem(unsigned long size, unsigned long align,
 690                               unsigned long goal)
 691 {
 692         unsigned long limit = 0;
 693
 694         return ___alloc_bootmem(size, align, goal, limit);
 695 }
 696
 697 static void * __init ___alloc_bootmem_node(bootmem_data_t *bdata,
 698                                 unsigned long size, unsigned long align,
 699                                 unsigned long goal, unsigned long limit)
 700 {
 701         void *ptr;
 702
 703         ptr = alloc_arch_preferred_bootmem(bdata, size, align, goal, limit);
 704         if (ptr)
 705                 return ptr;
 706
 707         ptr = alloc_bootmem_core(bdata, size, align, goal, limit);
 708         if (ptr)
 709                 return ptr;
 710
 711         return ___alloc_bootmem(size, align, goal, limit);
 712 }
 713
 714 /**
 715  * __alloc_bootmem_node - allocate boot memory from a specific node
 716  * @pgdat: node to allocate from
 717  * @size: size of the request in bytes
 718  * @align: alignment of the region
 719  * @goal: preferred starting address of the region
 720  *
 721  * The goal is dropped if it can not be satisfied and the allocation will
 722  * fall back to memory below @goal.
 723  *
 724  * Allocation may fall back to any node in the system if the specified node
 725  * can not hold the requested memory.
 726  *
 727  * The function panics if the request can not be satisfied.
 728  */
 729 void * __init __alloc_bootmem_node(pg_data_t *pgdat, unsigned long size,
 730                                    unsigned long align, unsigned long goal)
 731 {
 732         if (WARN_ON_ONCE(slab_is_available()))
 733                 return kzalloc_node(size, GFP_NOWAIT, pgdat->node_id);
 734
 735         return  ___alloc_bootmem_node(pgdat->bdata, size, align, goal, 0);
 736 }
 737
 738 void * __init __alloc_bootmem_node_high(pg_data_t *pgdat, unsigned long size,
 739                                    unsigned long align, unsigned long goal)
 740 {
 741 #ifdef MAX_DMA32_PFN
 742         unsigned long end_pfn;
 743
 744         if (WARN_ON_ONCE(slab_is_available()))
 745                 return kzalloc_node(size, GFP_NOWAIT, pgdat->node_id);
 746
 747         /* update goal according ...MAX_DMA32_PFN */
 748         end_pfn = pgdat->node_start_pfn + pgdat->node_spanned_pages;
 749
 750         if (end_pfn > MAX_DMA32_PFN + (128 >> (20 - PAGE_SHIFT)) &&
 751             (goal >> PAGE_SHIFT) < MAX_DMA32_PFN) {
 752                 void *ptr;
 753                 unsigned long new_goal;
 754
 755                 new_goal = MAX_DMA32_PFN << PAGE_SHIFT;
 756                 ptr = alloc_bootmem_core(pgdat->bdata, size, align,
 757                                                  new_goal, 0);
 758                 if (ptr)
 759                         return ptr;
 760         }
 761 #endif
 762
 763         return __alloc_bootmem_node(pgdat, size, align, goal);
 764
 765 }
 766
 767 #ifdef CONFIG_SPARSEMEM
 768 /**
 769  * alloc_bootmem_section - allocate boot memory from a specific section
 770  * @size: size of the request in bytes
 771  * @section_nr: sparse map section to allocate from
 772  *
 773  * Return NULL on failure.
 774  */
 775 void * __init alloc_bootmem_section(unsigned long size,
 776                                     unsigned long section_nr)
 777 {
 778         bootmem_data_t *bdata;
 779         unsigned long pfn, goal, limit;
 780
 781         pfn = section_nr_to_pfn(section_nr);
 782         goal = pfn << PAGE_SHIFT;
 783         limit = section_nr_to_pfn(section_nr + 1) << PAGE_SHIFT;
 784         bdata = &bootmem_node_data[early_pfn_to_nid(pfn)];
 785
 786         return alloc_bootmem_core(bdata, size, SMP_CACHE_BYTES, goal, limit);
 787 }
 788 #endif
 789
 790 void * __init __alloc_bootmem_node_nopanic(pg_data_t *pgdat, unsigned long size,
 791                                    unsigned long align, unsigned long goal)
 792 {
 793         void *ptr;
 794
 795         if (WARN_ON_ONCE(slab_is_available()))
 796                 return kzalloc_node(size, GFP_NOWAIT, pgdat->node_id);
 797
 798         ptr = alloc_arch_preferred_bootmem(pgdat->bdata, size, align, goal, 0);
 799         if (ptr)
 800                 return ptr;
 801
 802         ptr = alloc_bootmem_core(pgdat->bdata, size, align, goal, 0);
 803         if (ptr)
 804                 return ptr;
 805
 806         return __alloc_bootmem_nopanic(size, align, goal);
 807 }
 808
 809 #ifndef ARCH_LOW_ADDRESS_LIMIT
 810 #define ARCH_LOW_ADDRESS_LIMIT  0xffffffffUL
 811 #endif
 812
 813 /**
 814  * __alloc_bootmem_low - allocate low boot memory
 815  * @size: size of the request in bytes
 816  * @align: alignment of the region
 817  * @goal: preferred starting address of the region
 818  *
 819  * The goal is dropped if it can not be satisfied and the allocation will
 820  * fall back to memory below @goal.
 821  *
 822  * Allocation may happen on any node in the system.
 823  *
 824  * The function panics if the request can not be satisfied.
 825  */
 826 void * __init __alloc_bootmem_low(unsigned long size, unsigned long align,
 827                                   unsigned long goal)
 828 {
 829         return ___alloc_bootmem(size, align, goal, ARCH_LOW_ADDRESS_LIMIT);
 830 }
 831
 832 /**
 833  * __alloc_bootmem_low_node - allocate low boot memory from a specific node
 834  * @pgdat: node to allocate from
 835  * @size: size of the request in bytes
 836  * @align: alignment of the region
 837  * @goal: preferred starting address of the region
 838  *
 839  * The goal is dropped if it can not be satisfied and the allocation will
 840  * fall back to memory below @goal.
 841  *
 842  * Allocation may fall back to any node in the system if the specified node
 843  * can not hold the requested memory.
 844  *
 845  * The function panics if the request can not be satisfied.
 846  */
 847 void * __init __alloc_bootmem_low_node(pg_data_t *pgdat, unsigned long size,
 848                                        unsigned long align, unsigned long goal)
 849 {
 850         if (WARN_ON_ONCE(slab_is_available()))
 851                 return kzalloc_node(size, GFP_NOWAIT, pgdat->node_id);
 852
 853         return ___alloc_bootmem_node(pgdat->bdata, size, align,
 854                                 goal, ARCH_LOW_ADDRESS_LIMIT);
 855 }